[WHEELER] THERMAL EXPANSION OF ROCK 33 
In some cases, as will be seen from the foregoing tables, there 
seemed to be a very slight change in the length of the diabase cylinder 
in the few days that elapsed between two sets of observations. How- 
ever, it seems possible that this may have been due to some experi- 
mental error, especially as the changes are quite small. 
The length of the cylinder after the six heatings was measured with 
the vernier calipers (Feb. 1, 1910) and was found to be 20.048 cms. 
This gives a permanent expansion of .217 cms. over the original length 
of 19.831 cms., which agrees very well with the value obtained from the 
micrometer microscope readings, 2.e., .2175 cms. 
The next rock to be examined was a specimen of granite from 
Westerly, R.I., U.S.A., described in the work by Dr. Adams and Dr. 
Coker as a “fresh, very fine grained, massive, pale, pink granite,” 
“composed essentially of biotite, microcline, orthoclase and quartz.” 
As the method of procedure was identical with that for the diabase, 
only the results obtained are given. Its length, at a temperature of 
19° C, as found by the vernier calipers, was 19.833 cms. before heating. 
The granite was likewise subjected to six sucessive heatings with results 
as follows (See also Figure V.): 









| 
Results of First Results of Second Results of Third 
Heating. Heating. Heating. 
Tempera- Total Ex- Tempera- | Total Ex- | Tempera-| Total Ex- 
ture. pansion. ture. pansion. ture pansion. 
19°C. O mm 19°C. | 4.029 mm 19°C 4.419 mm. 
172.5 .261 190.5 4.220 202.5 4.646 
371 .960 339.9 4.384 439.5 4.914 
465 1.475 480 4.601 604.5 5.208 
592 2.440 664 5.074 751 5.925 
708 3.439 SOEUR PRE EE 5.700 
819 4.442 874 5.392 997.5 5.985 
936.5 4.843 984 5.639 1037 6.156 
1021.5 5.418 1037 5.858 861.5 5.610 
915.5 5.139 885 5.389 670.5 5.291 
785 4.920 581 4.915 475.5 5.034 
632 4.748 18 4.419 18 4.638 
415 PEAR tell) Weis Cichs 50 ail SNS | ct cys lala 
291 AP eer NRO We Lites ARR AR SES De 01 OO OI 
19 EAU AE PUB PE INR LAS ARE ESA Le hr AS 


Sec. III., 
1910. 3. 


